1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LEDs driver for GPIOs 4 * 5 * Copyright (C) 2007 8D Technologies inc. 6 * Raphael Assenat <raph@8d.com> 7 * Copyright (C) 2008 Freescale Semiconductor, Inc. 8 */ 9 #include <linux/err.h> 10 #include <linux/gpio.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/kernel.h> 13 #include <linux/leds.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/platform_device.h> 17 #include <linux/property.h> 18 #include <linux/slab.h> 19 #include "leds.h" 20 21 struct gpio_led_data { 22 struct led_classdev cdev; 23 struct gpio_desc *gpiod; 24 u8 can_sleep; 25 u8 blinking; 26 gpio_blink_set_t platform_gpio_blink_set; 27 }; 28 29 static inline struct gpio_led_data * 30 cdev_to_gpio_led_data(struct led_classdev *led_cdev) 31 { 32 return container_of(led_cdev, struct gpio_led_data, cdev); 33 } 34 35 static void gpio_led_set(struct led_classdev *led_cdev, 36 enum led_brightness value) 37 { 38 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 39 int level; 40 41 if (value == LED_OFF) 42 level = 0; 43 else 44 level = 1; 45 46 if (led_dat->blinking) { 47 led_dat->platform_gpio_blink_set(led_dat->gpiod, level, 48 NULL, NULL); 49 led_dat->blinking = 0; 50 } else { 51 if (led_dat->can_sleep) 52 gpiod_set_value_cansleep(led_dat->gpiod, level); 53 else 54 gpiod_set_value(led_dat->gpiod, level); 55 } 56 } 57 58 static int gpio_led_set_blocking(struct led_classdev *led_cdev, 59 enum led_brightness value) 60 { 61 gpio_led_set(led_cdev, value); 62 return 0; 63 } 64 65 static int gpio_blink_set(struct led_classdev *led_cdev, 66 unsigned long *delay_on, unsigned long *delay_off) 67 { 68 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 69 70 led_dat->blinking = 1; 71 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, 72 delay_on, delay_off); 73 } 74 75 static int create_gpio_led(const struct gpio_led *template, 76 struct gpio_led_data *led_dat, struct device *parent, 77 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set) 78 { 79 struct led_init_data init_data = {}; 80 int ret, state; 81 82 led_dat->cdev.default_trigger = template->default_trigger; 83 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); 84 if (!led_dat->can_sleep) 85 led_dat->cdev.brightness_set = gpio_led_set; 86 else 87 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; 88 led_dat->blinking = 0; 89 if (blink_set) { 90 led_dat->platform_gpio_blink_set = blink_set; 91 led_dat->cdev.blink_set = gpio_blink_set; 92 } 93 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) { 94 state = gpiod_get_value_cansleep(led_dat->gpiod); 95 if (state < 0) 96 return state; 97 } else { 98 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 99 } 100 led_dat->cdev.brightness = state; 101 led_dat->cdev.max_brightness = 1; 102 if (!template->retain_state_suspended) 103 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 104 if (template->panic_indicator) 105 led_dat->cdev.flags |= LED_PANIC_INDICATOR; 106 if (template->retain_state_shutdown) 107 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; 108 109 ret = gpiod_direction_output(led_dat->gpiod, state); 110 if (ret < 0) 111 return ret; 112 113 if (template->name) { 114 led_dat->cdev.name = template->name; 115 ret = devm_led_classdev_register(parent, &led_dat->cdev); 116 } else { 117 init_data.fwnode = fwnode; 118 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, 119 &init_data); 120 } 121 122 return ret; 123 } 124 125 struct gpio_leds_priv { 126 int num_leds; 127 struct gpio_led_data leds[]; 128 }; 129 130 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) 131 { 132 struct device *dev = &pdev->dev; 133 struct fwnode_handle *child; 134 struct gpio_leds_priv *priv; 135 int count, ret; 136 137 count = device_get_child_node_count(dev); 138 if (!count) 139 return ERR_PTR(-ENODEV); 140 141 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); 142 if (!priv) 143 return ERR_PTR(-ENOMEM); 144 145 device_for_each_child_node(dev, child) { 146 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds]; 147 struct gpio_led led = {}; 148 149 /* 150 * Acquire gpiod from DT with uninitialized label, which 151 * will be updated after LED class device is registered, 152 * Only then the final LED name is known. 153 */ 154 led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child, 155 GPIOD_ASIS, 156 NULL); 157 if (IS_ERR(led.gpiod)) { 158 fwnode_handle_put(child); 159 return ERR_CAST(led.gpiod); 160 } 161 162 led_dat->gpiod = led.gpiod; 163 164 led.default_state = led_init_default_state_get(child); 165 166 if (fwnode_property_present(child, "retain-state-suspended")) 167 led.retain_state_suspended = 1; 168 if (fwnode_property_present(child, "retain-state-shutdown")) 169 led.retain_state_shutdown = 1; 170 if (fwnode_property_present(child, "panic-indicator")) 171 led.panic_indicator = 1; 172 173 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 174 if (ret < 0) { 175 fwnode_handle_put(child); 176 return ERR_PTR(ret); 177 } 178 /* Set gpiod label to match the corresponding LED name. */ 179 gpiod_set_consumer_name(led_dat->gpiod, 180 led_dat->cdev.dev->kobj.name); 181 priv->num_leds++; 182 } 183 184 return priv; 185 } 186 187 static const struct of_device_id of_gpio_leds_match[] = { 188 { .compatible = "gpio-leds", }, 189 {}, 190 }; 191 192 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 193 194 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 195 const struct gpio_led *template) 196 { 197 struct gpio_desc *gpiod; 198 unsigned long flags = GPIOF_OUT_INIT_LOW; 199 int ret; 200 201 /* 202 * This means the LED does not come from the device tree 203 * or ACPI, so let's try just getting it by index from the 204 * device, this will hit the board file, if any and get 205 * the GPIO from there. 206 */ 207 gpiod = devm_gpiod_get_index(dev, NULL, idx, GPIOD_OUT_LOW); 208 if (!IS_ERR(gpiod)) { 209 gpiod_set_consumer_name(gpiod, template->name); 210 return gpiod; 211 } 212 if (PTR_ERR(gpiod) != -ENOENT) 213 return gpiod; 214 215 /* 216 * This is the legacy code path for platform code that 217 * still uses GPIO numbers. Ultimately we would like to get 218 * rid of this block completely. 219 */ 220 221 /* skip leds that aren't available */ 222 if (!gpio_is_valid(template->gpio)) 223 return ERR_PTR(-ENOENT); 224 225 if (template->active_low) 226 flags |= GPIOF_ACTIVE_LOW; 227 228 ret = devm_gpio_request_one(dev, template->gpio, flags, 229 template->name); 230 if (ret < 0) 231 return ERR_PTR(ret); 232 233 gpiod = gpio_to_desc(template->gpio); 234 if (!gpiod) 235 return ERR_PTR(-EINVAL); 236 237 return gpiod; 238 } 239 240 static int gpio_led_probe(struct platform_device *pdev) 241 { 242 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); 243 struct gpio_leds_priv *priv; 244 int i, ret = 0; 245 246 if (pdata && pdata->num_leds) { 247 priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, pdata->num_leds), 248 GFP_KERNEL); 249 if (!priv) 250 return -ENOMEM; 251 252 priv->num_leds = pdata->num_leds; 253 for (i = 0; i < priv->num_leds; i++) { 254 const struct gpio_led *template = &pdata->leds[i]; 255 struct gpio_led_data *led_dat = &priv->leds[i]; 256 257 if (template->gpiod) 258 led_dat->gpiod = template->gpiod; 259 else 260 led_dat->gpiod = 261 gpio_led_get_gpiod(&pdev->dev, 262 i, template); 263 if (IS_ERR(led_dat->gpiod)) { 264 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n", 265 template->gpio, template->name); 266 continue; 267 } 268 269 ret = create_gpio_led(template, led_dat, 270 &pdev->dev, NULL, 271 pdata->gpio_blink_set); 272 if (ret < 0) 273 return ret; 274 } 275 } else { 276 priv = gpio_leds_create(pdev); 277 if (IS_ERR(priv)) 278 return PTR_ERR(priv); 279 } 280 281 platform_set_drvdata(pdev, priv); 282 283 return 0; 284 } 285 286 static void gpio_led_shutdown(struct platform_device *pdev) 287 { 288 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 289 int i; 290 291 for (i = 0; i < priv->num_leds; i++) { 292 struct gpio_led_data *led = &priv->leds[i]; 293 294 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 295 gpio_led_set(&led->cdev, LED_OFF); 296 } 297 } 298 299 static struct platform_driver gpio_led_driver = { 300 .probe = gpio_led_probe, 301 .shutdown = gpio_led_shutdown, 302 .driver = { 303 .name = "leds-gpio", 304 .of_match_table = of_gpio_leds_match, 305 }, 306 }; 307 308 module_platform_driver(gpio_led_driver); 309 310 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 311 MODULE_DESCRIPTION("GPIO LED driver"); 312 MODULE_LICENSE("GPL"); 313 MODULE_ALIAS("platform:leds-gpio"); 314